This invention relates generally to an improved permanent magnet and more particularly to an improved permanent magnet including predominantly an alloy of Sm.sub.2 Co.sub.17 crystals having a predominantly columnar macrostructure and to a process for preparing the improved permanent magnets.
Permanent magnet compositions including a samarium alloy, such as, Sm.sub.2 Co.sub.17 are known to provide improved magnetic properties over conventional Alnico magnets. Such magnets are described in U.S. Pat. No. 4,289,549 issued to kazutomo Kasai on Sept. 15, 1981 and assigned to the same assignee as the subject application. In connection with conventional Alnico magnets, it is known that a cast structure provides magnets with columnar crystalization. These permanent magnets are described in Magnets with Columnar Crystallization by J. E. Gould in Cobalt, No. 23 (June, 1964, pp 82-87).
While the resin-bonded permanent magnet composition disclosed in the patent to Kasai are superior to many prior art compositions, magnet compositions having even more improved magnetic properties are still required. Accordingly, it is desirable to provide powder-bonded type permanent magnet compositions having improved crystal anisotropy.